We don't have synonyms for plus-fours yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are plus fours.
(n) :
Wide knickerbocker breeches, so called because originally they were designed with four inches of excess material so as to hang in a fold below the fastening beneath the knee; traditionally associated with sports, especially golf.
(n) :
Wide knickerbocker breeches, so called because originally they were designed with four inches of excess material so as to hang in a fold below the fastening beneath the knee; traditionally associated with sports, especially golf.